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L’Hospital’s Rule. L’Hospital’s Rule: In cases in which an indeterminate form occurs, if the limit of f(x)/g(x) exists it is equivalent to the limit of f’(x)/g’(x). Indeterminate forms: 0/0, ∞/∞, and -∞/-∞. -2 2 -4=0 -2+2=0. f’(x)=2x g’(x)=1. 4. e ∞ =∞ 5∞ 2 =∞. f’(x)=e x g’(x)=10x.
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L’Hospital’s Rule: In cases in which an indeterminate form occurs, if the limit of f(x)/g(x) exists it is equivalent to the limit of f’(x)/g’(x). Indeterminate forms: 0/0, ∞/∞, and -∞/-∞
-22-4=0 -2+2=0 f’(x)=2x g’(x)=1 4
e∞=∞ 5∞2 =∞ f’(x)=ex g’(x)=10x f’’(x)=ex g’’(x)=10 =∞
Indeterminate Products If f(x)*g(x) results in the indeterminate form 0*∞, by rearranging the function to f/(1/g) or g/(1/f) we convert the product to the indeterminate form 0/0 or ∞/∞, and can use L’Hospital’s rule to evaluate the limit. Example limx->0+xlnx limx->0+x= 0 limx-> 0+lnx= ∞ If we evaluate the limit of each function, the product is the indeterminate form 0*∞. limx->0+lnx/(1/x) limx->-∞ (1/x)/(-1/x2) limx->0+-x2/x limx->0+-x = 0